I spent most of the summer reporting and writing a feature story about Safra Catz, the enigmatic co-president of Oracle (ORCL).  I talked to oodles of people about Catz’s ambitions, her value to the company, the likelihood of her becoming CEO, and her relationship with Charles Phillips, Oracle’s other co-president.

All this is in the article, published in the current issue of Fortune. The conclusion is that Catz is a complicated, competent, intelligent pile-driver of an executive who makes Oracle hum.

Left explicitly unsaid in the quest to find out as much as possible about Safra Catz is just how successful her boss, Larry Ellison, has been as CEO of Oracle. This was my single greatest takeaway from my reporting.

There was a period, years ago, when Ellison became disengaged from actively running the company. Because his extracurricular activities get so much attention — the America’s Cup battles, the yachts, the homes, the marriages, and so on — the world that watches Oracle from afar doesn’t quite get that Ellison’s era of disengagement ended a long time ago.

The Steve Jobs of enterprise software?

Like his buddy, Apple (AAPL) CEO Steve Jobs, there certainly are things Ellison doesn’t want to do. He’s just not that into finance. (He’s into money, of course, and is as tight-fisted with Oracle’s cash as he free-spending with his own.)

He’s a known enemy of operational details. The comparisons with Jobs and Apple (AAPL) go further, in fact. In Catz, Ellison had the confidence, maturity and discipline to hire a get-it-done No. 2, just as Jobs has done with Tim Cook, whom I’ve also spent some time on.

Both founders are technically proficient industry visionaries who’ve been through disastrous downs and stratospheric ups. (Oracle hit the skids in the early 90s, when Jobs was exiled from Apple.)

The point about Ellison is that he has done just what a CEO should do. He knows so much about his product that the technical people respect him and don’t try to B.S. him.

A clear vision, plus trusted lieutenants

He trusts his operational lieutenants enough to do their jobs. He sets overall direction for the company. Critically, he changed his mind at a moment when doing so made all the difference. For years Oracle, like Apple to this day, didn’t do much in the way of acquisitions. Ellison’s epiphany that organic (that is, in-house) growth wasn’t going to be good enough is the reason that Oracle has trounced SAP (SAP), Microsoft (MSFT) and anyone else in its way over the past half decade.

(Late Wednesday Oracle announced fiscal first quarter earnings of $1.12 billion, or 22 cents a share, 4.4% from $1.08 billion a year earlier. Margins climbed to almost 35%, from 28.5% – all during a quarter in which revenues fell slightly.)

It’s worth noting that hiring ex-banker Catz and ex-analyst Phillips, both strategically minded and acquisition-friendly executives, coincided with Ellison’s change of heart. The point is the same, though. If the people he hired helped him see the light, bully for him. Ellison gets to take credit.

Much is also made of Ellison’s long absences from the office and his distractedness. The business world and investors should greet such talk with two words: Who cares? Ellison’s cell phone keeps him as close to Oracle as he needs to be. When important things are happening Ellison is a constant presence at Oracle.

At a youthful 65 he quite likely will be running his show for years to come. Eventually people may even stop wondering how much credit for it all he deserves because the answer will be apparent: A whole lot.